Just an opinion but I dont think the expense of the "deepening" would justify the expense . Just not that much room to play with , the two or so extra grains of powder wouldnt really produce much more , plus burn would help kill any added expections . Could be wrong though , would welcome rebuttle .

I was trying to measure and do some estimating.I think you are right about a 2 grain increase or there about, my guesstimation puts it less than 3. I was hoping to hear that somebody had done it and got an additional 5 grains. That would be worth it especially for a DIY kinda person.

I have not heard about deepening the chambers to a Remington 1858 but I know David Clements in Virginia will deepen the chambers on a Ruger Old Army cylinder. From what I understand, the process will add 75 to 100 fps with the increased powder charge.

Deepening your chambers is the wrong way to go. Just upgrade your choice of powders to either Swiss or Triple 7. Both will produce more velocity per grain than the other black powders out there on the market.

I have never understood the concept of "Pushing the Envelope" for a particular caliber. Generally guns shoot most accurately with a moderate load, not a heavy one.

If you want a charcoal burner that has more "BANG" then I suggest a replica Walker or replica Dragoon. An accurate "moderate" load with either of those revolvers would have more velocity and knock down power than a Remmie with a deepened (and weakened) chamber.

It depends of which era Replicas we are talking about. Those Percussion replicas made before the year 2000, usually had cylinder chambers that were "Funneled" with metal steps in them. Toda6ys replicas are strait walled and generally there is no need to take any more metal out, with the advent of Hotter more powerful powders like Triple Seven, Swiss, Goex Old Eyensford, Black Mag 3 ,Black MZ, Pyrodex, Super Powder, etc the newer strait walled cylinder will suffice as in hunting purposes. The older cylinders especially in Colts I recommend those who wish to hunt with them to take out the extra metal. There is no structural problem or weakness in doing so, provided it is correctly done. My friend Master Black Powder Gunsmith Mr. Dykes Reber of the Muzzleloader Shop in N Little Rock Ark. He offers this and all major repairs and modifications on Percussion Revolvers. You can contact his shop at 501) 758-2222.

If all you are wanting is a "bigger boom", consider the Uberti Walker with a .45 BPM conversion cylinder. There's a feller named Mike Brackett who is a wizard with any bp Colt charcoal burner, give him a holler and tell him yer wanting a .45 BPM and he'll hook you right up with the bone-deep concussive waves you're craving apparently, ha ha!